Device for manufacturing blades for the blade wheel of an axial flow machine

ABSTRACT

Blades which are to be attached to the blade wheel of an axial flow machine, have a paddle part and an attachment surface which are simultaneously shaped in two molds. One of these molds shapes the paddle part in the desired manner while the other mold imparts the final shape to the attachment surface. Then the two molds with the blade still clamped in them are twisted to produce the desired blade angle.

United States Patent lnventor Martti Heinonen Turku, Finland Appl. No.738,547 Filed June 20, 1968 Patented May 25, 1971 Assignee Valmet 0yHelsinki, Finland Priority June 21, 1967 Finland 1753/67 DEVICE FORMANUFACTURING BLADES FOR THE BLADE WHEEL OF AN AXIAL FLOW MACHINE 5Claims, 6 Drawing Figs. A

Int. Cl 821d 41/02 Field of Search 72/299,

316, 404, 371; 29/156.8, 156 (B), 156 (CF), 156 (FC), 156 (H), 156 (P),156 (T), 23.5

[56] References Cited UNITED STATES PATENTS 3,012,308 12/1961 Zech etal. 29/l56.8 2,843,919 7/1958 Garaventa et al... 29/l56.8 2,389,87611/1945 Sequin 29/l56.8 2,61 1,414 9/1952 Sampatacos 72/299 PrimaryExaminerCharles W. Lanham Assistant Examiner-Michael J. KeenanAnomey-Richards and Geier ABSTRACT: Blades which are to be attached tothe blade wheel of an axial flow machine, have a paddle part and an attachment surface which are simultaneously shaped in two moldsv One ofthese molds shapes the paddle part in the desired manner while the othermold imparts the final shape to the attachment surface. Then the twomolds with the blade still clamped in them are twisted to produce thedesired blade angle.

Patented May 25, 1971 3,580,039

2 Sheets-Sheet 1 MA'RTT/ HFINUA/FN MVE/V T 73 Patented May 25, 1971 2Sheets-Sheet 2 FIG. 4

MA'RTTI HE/NOA/EN rek/V5345 DEVICE FOR MANUFACTURING BLADES FOR THEBLADE WHEEL OF AN AXIAL FLOW MACHINE The present invention concerns amethod and a device for manufacturing blades, to be made of sheetmaterial, for blade wheels of axial flow machines, in particular of airblowers.

Prior art includes the manufacturing of such blade wheels either in onepiece of sheet material or from a separate hub part and from bladesattached to it e.g. by riveting or by weldmg.

In order that a shape consistent with good flow characteristics might begiven to such blade wheels made of sheet material, tools and jigs ofrather complicated shape are required. For instance when a set of bladewheels comprising various sizes has to be made, individual tools andjigs have to be made for each size. This tends to confine theapplication of the method because the making of expensive tools and jigsimplies large manufacturing series.

The aim of the present invention is to eliminate these drawbacks. Theintention is to manufacture the blades of a blade wheel assembled fromparts with the aid of very simple .tools and fixtures, which may in partalso be used for different sizes of a flow machine series, e.g. of ablower series. It is further intended that with the aid of these simpletools and fixtures blades of blade wheels might be manufactured whichhave different blade angles, an accomplishment which has not beenpossible by any previously known methods.

In the present invention the problem outlined above has been solved invery simple manner. A method according to the invention is mainlycharacterized in that the paddle part of the blade and its attachmentsurface are both shaped in separate molds and that they are twistedwhile clamped in their molds in such manner with reference to each otherthat a blade angle of desired magnitude is obtained.

A device according to the present invention, again, is mainlycharacterized in that the parts of the device shaping the paddle part ofthe blade and its attachment surface, respectively, are tumable withreference to each other so that it is possible with the aid of thedevice to manufacture blades having different blade angles.

By using the method and the device, the manufacturing of numerous andcomplex tools and jigs is avoided. For instance, if the paddle surfaceof an axial blower has cylindrical shape, the tool which is used forshaping the paddle is inexpensive and simple because the shape-producingsurfaces of the tool, most suitably a mold consisting-of two parts, arecylindrical surfaces, which may be produced e.g. on the lathe. Again, if

the hub piece has the character of a plane, the attachment surfaces ofthe blade can be shaped as planes. In both instances the same tools,that is the same molds, can be used for all blade sizes of a givenblower series. It is to be understood, of course, that the paddlesurface of the blade, and consequently also the mold surface producingits shape, can be given any other plane or curved shape other thancylindrical. When blade wheels are manufactured for varying purposes, itis possible in a device according to the invention to change merely themolds shaping the paddle part and/or the attachment surface to suit thepurpose in question. Since furthermore the parts of the device shapingthe paddle part of the blade and the attachment surface, respectively,are tumable with reference to each other while both parts of the blade,to wit, the paddle part and the attachment part, are simultaneouslyclamped in them, the blade can be imparted any desired blade angle asmay be required. If, moreover, the elements imparting rotatory motion tothe device are so arranged that twisting can be effected in eitherdirection, one and the same device may be used in manufacturing bladesto fit both lefthanded and right-handed blade wheels.

The invention is described in closer detail with reference to theattached drawing, in which:

FIG. 1 displays part of the blade wheel of an axial blower, seen fromthe direction of entering air,

FIG. 2 shows'a blade as in FIG. I, seen from one side,

FIG. 3 shows a section of a blade as in FIG. 1, viewed from thedirection of the hub,

FIG. 4 shows a device for manufacturing a blade as in FIG. I, viewedfrom the side and partly in section,

FIG. 5 shows a device as in FIG. 4, in top view, and

FIG. 6 shows the mold, constituting a part of a device as in FIG. 4,which shapes the paddle part of the blade, viewed from the end of thedevice.

In FIG. 1, the reference numeral 1 indicates the hub piece of the bladewheel, to which the blades 2 have been attached by spot welding, weldingor riveting, only two such blades having been depicted in the figure.The partly dotted outline abcdefg in FIG. 1 represents the shape of theblade blank before its shaping with the aid of a device according to theinvention. The solid outline abcd'e'fg represents a blade shaped by amethod according to the invention, after completed shaping. The partc'd'e'f h of the blade is understood to be the paddle part of the blade,to which in the mold a shape consistent with favorable flowcharacteristics, e.g. the shape of a cylinder surface, has beenimparted. The part abhg of the blade, again, is understood to be theattachment surface of the blade, which in this instance is a plane andwhich will be attached to the hub piece 1. The parts bc'h and gf h ofthe blade are understood to be parts of the sheet which remain betweenthe paddle part and attachment surface of the shaped blade, which haveapproximately triangular shape and which on rotation of the molds withreference to each other are twisted, with reference to the plane of theattachment surface, by an angle consistent with the blade angle a. InFIG. 3 the projection of the blade as seen from the direction of the hubhas been shown and the blade angle a has been indicated, which is thusunderstood to be the angle between the cord drawn to the profile of theroot portion of the paddle and the attachment plane.

The device presented in FIGS. 4 and 5 comprises for the shaping ofblades a mold 3,311 consisting of two parts, which shapes the regionc'def'h (FIG. 1) of the blade paddle. In FIG. 4 the mold 3,3a and theblade 2 have been shown in section. In FIG. 6 the mold 3,3a has beenshown as seen from the end of the device, and the figure disclosesbetween the mold halves 3 and 3a a gap 10, in which the proper shape isimparted to the said paddle part. In the embodiment illustrated by FIG.4 the lower mold 3a has been mounted on a lower stand 6 and the uppermold 3 has been fixed to a vertically movable table 7. This table ismoved e.g. by a hydraulic press 8, the reference numeral 9 indicatingthe piston of this press.

Furthermore, the device comprises a twisting jaw 4, which has a slit 5at its end pointing towards the workpiece. The twisting jaw is axiallydisplaceable with the aid of the push press 13, the reference numeral 14indicating the piston of this press. The axial movement of the twistingjaw 4 is guided by the bearings 11 and 12. The position of the twistingjaw 4 indicated with dotted lines in FIG. 5 represents its workingposition proper. The twisting jaw is moreover tumable about its axis bymeans of an arm 15 attached to it and of a press 16 moving this arm. Thereference numeral 17 indicates the piston of the press 16.

The operation of the device is very simple. The paddle part cdef of theblade blank out from sheet material is placed upon the mold half 3a andthe blank is pressed by means of the upper mold 3 to assume the shape ofthe gap 10. The twisting jaw 4 is pushed with the aid of the press 13 toimpact the attachment surface abhg of the blade blank. The twisting jawis turned or rotated with the aid of the arm 15 and the press 16 aboutits longitudinal axis to the extent that the desired blade angle isachieved. The travel of the piston 17 is adjustable, and different bladeangles suited to each individual application can thus be imparted to theshaped blade surface. The twisting jaw 4 may be provided with elementsby means of which the direction in which it is turned can be reversed,whereby the device may be used to manufacture blades for right-hand aswell as left-hand blade wheels.

It is thus noted that with the aid of very simple tools, that is molds,of the kind which has been described above blades of sheet material forblade wheels of many different shapes and different sizes may bemanufactured, and which blades may with the same device be made to havethe blade angle a consistent with each particular type of blade wheel.

The invention is not confined to the example presented, but it may bevaried within the scope of the patent claims. For instance, the gap inthe pressure mold 3,30 may equally have the shape of some other surfacewith favorable flow characteristics. The shape of the twisting jaw 4 mayalso vary; it may for instance equally be a mold consisting of twoparts, but which obviously has to be turnable with reference to the mold3,3a. The elements causing the molds and the twisting jaw to move mayequally be of some other design known in prior art than that presentedin the example. It is obvious that the device may be made automaticallyoperating, by means of arrangements in themselves known in prior art.

I claim:

1. A method of manufacturing blades for the blade wheel of an axial flowmachine, each of said blades having a paddle part and a hub attachmentpart, said method comprising simultaneously separately clamping andshaping in final form the paddle part and the attachment part and thentwisting the parts relatively to each other while continuing to clampthem to provide a desired blade angle.

2. A device for manufacturing blades for the blade wheel of an axialflow machine, each of said blades having a paddle part and a hubattachment part, said device comprising a mold for clamping and shapingin final form the paddle part, a separate mold for simultaneouslyclamping and shaping in final form the attachment part, and meanstwisting at least one of said molds relatively to the other mold whilethe molds clamp said parts to impart to the blade a desired blade angle.

3. Device as in claim 2, characterized that one or both parts of thedevice shaping the paddle and the attachment surface is/are a pressuremold consisting of two parts.

4. Device as in claim 2, characterized in that one or both parts of thedevice shaping the parts of the blade is/are a mold in principleconsisting of one piece and having a slit which when pushed upon theblade blank shapes it as desired.

5. Device as in claim 2, characterized in that the mutual position anddirection of rotation of the molds shaping the parts of the blade arereversible so that with one and the same device blades appropriate forboth right-hand and left-hand blade wheels may be manufactured.

1. A method of manufacturing blades for the blade wheel of an axial flow machine, each of said blades having a paddle part and a hub attachment part, said method comprising simultaneously separately clamping and shaping in final form the paddle part and the attachment part and then twisting the parts relatively to each other while continuing to clamp them to provide a desired blade angle.
 2. A device for manufacturing blades for the blade wheel of an axial flow machine, each of said blades having a paddle part and a hub attachment part, said device comprising a mold for clamping and shaping in final form the paddle part, a separate mold for simultaneously clamping and shaping in final form the attachment part, and means twisting at least one of said molds relatively to the other mold while the molds clamp said parts to impart to the blade a desired blade angle.
 3. Device as in claim 2, characterized that one or both parts of the device shaping the paddle and the attachment surface is/are a pressure mold consisting of two parts.
 4. Device as in claim 2, characterized in that one or both parts of the device shaping the parts of the blade is/are a mold in principle consisting of one piece and having a slit which when pushed upon the blade blank shapes it as desired.
 5. Device as in claim 2, characterized in that the mutual position and direction of rotation of the molds shaping the parts of the blade are reversible so that with one and the same device blades appropriate for both right-hand and left-hand blade wheels may be manufactured. 